Accuracy of modified Haigis method calculates for intraocular lens refractive degree after myopic refractive surgery

Abstract

AIM: To compare and modify the accuracy of the Haigis formula calculates for intraocular lens(IOL)refraction after myopic excimer laser surgery.METHODS: The clinical records of 31 patients(31 eyes)who firstly accepted myopic corneal refractive surgery(LASIK/PRK)and then underwent phacomulsification was combined with IOL implantation in Tianjin Eye Hospital between February 2014 and March 2019 were finally enrolled in this study. Postoperative refraction was performed at least 6mo after cataract surgery. To compare the accuracy of equivalent keratometry readings(EKR)of different corneal radius(2.0, 3.0, 4.0, 4.5, 5.0mm)combined with the Haigis formula to calculate the IOL diopter after myopia, obtain the modified Haigis formula, and then compare the modified Haigis formula with the accuracy of Barrett true K, Haigis-L and Shammas-PL formulas for calculating IOL diopter after myopia.RESULTS: The median absolute error(MedAE)and mean absolute error(MAE)of 4.0mm EKR Haigis formula was significantly lower than that of 4.5mm and 5.0mm EKR(all P0.05).CONCLUSION: Haigis formula combined with the 4.0mm EKR can be used to calculate the IOL power in eyes after myopic LASIK/PRK, and its accuracy is comparable to the Barrett true K formula. However, the longer the AL is, the higher the possibility of hyperopic drift postoperatively might occur with the modified Haigis.

Keywords

• intraocular lens refractive calculation
• myopia
• refractive surgery
• haigis
• equivalent keratometry